Fri Oct 10 12:20:59 UTC 2025: Okay, here’s a summary and rewritten news article based on the provided text:
**Summary:**
Indian researchers have developed a novel method using luminescence dating of quartz grains in sand dikes to precisely date ancient earthquakes. Sand dikes, formed during seismic events due to liquefaction, trap clean sand that has been heated significantly during the process, erasing previous luminescence signals. By measuring the new luminescence signal accumulated in the quartz grains, scientists can accurately determine when the sand dike formed, thereby dating the earthquake that caused it. The technique has been validated using samples from northeastern India and provides a more direct way to understand past seismic activity, which is crucial for improving earthquake preparedness and building codes.
**News Article:**
**Indian Scientists Unveil New Technique for Dating Ancient Earthquakes**
*Hyderabad, October 10, 2025* – A team of Indian researchers has announced a breakthrough in paleoseismology, developing a new method to accurately date ancient earthquakes using luminescence signals found in sand dikes. This innovative technique offers a more precise way to understand earthquake history, particularly in regions lacking comprehensive historical seismic records.
The collaborative research, led by scientists from CSIR–National Geophysical Research Institute (NGRI) in Hyderabad and involving multiple other prominent Indian institutions, focuses on sand dikes. These geological features are formed when intense seismic shaking causes water-saturated sediment to liquefy, injecting a mixture of sand and water into cracks in the ground. According to Dr. Devender Kumar, Chief Scientist at CSIR-NGRI, “A sand dike serves as clear evidence of a major earthquake.”
The key to the new dating method lies in the heat generated during the sand dike formation process. As sand and water are violently injected into cracks, the inter-grain friction produces temperatures exceeding 350°C, effectively erasing any previously accumulated luminescence signals in the quartz grains within the sand. Subsequently, these grains begin to accumulate a new luminescence signal, which can be measured using Optically Stimulated Luminescence (OSL) dating to determine the timing of the dike formation and, consequently, the earthquake’s occurrence.
“Our team proposed that inter-grain friction during this process generates enough heat, and this frictional heat can exceed 350C erasing previously accumulated geological luminescence in the quartz grains present in the dike sediments. Subsequently, the grains begin accruing a new luminescence signal, which can be measured to determine the timing of the dike formation — and thus, the earthquake’s occurrence,” said CSIR-NGRI Chief Scientist and corresponding author Devender Kumar.
The research team validated their findings by analyzing sediment samples from five sand dikes in northeastern India, confirming that the quartz grains had indeed been subjected to sufficient heat to reset their luminescence signals.
The implications of this new dating method are significant. By providing a more accurate understanding of earthquake frequency and magnitude in the past, scientists can better assess future seismic risks. This knowledge is essential for improving building safety codes, designing effective earthquake mitigation strategies, and ultimately protecting communities from the devastating effects of earthquakes.
The study, published in *Earth and Planetary Science Letters*, has already garnered significant international attention within the scientific community. It promises to be a valuable tool for researchers worldwide working to unravel the mysteries of earthquake history and improve earthquake preparedness.
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